Automatic arc-regulator



J. E. SOONS AND H. ROBINSON.

AUTOMATIC ARC REGULATOR.

. APPLICATION FILED NOV. 15. 1919.

1,374,404. Patented Apr. 12, 1921.

3 SHEETS-SHEET I.

8' I a W Z fl nnomrsr.

- J. E. soows AND H. ROBINSON.

AUTOMATIC ARC REGULATOR.

APPLICATION FILED NOV.15, 1919- 1,374,404. Patented Apr. 12, 1921.

3 SHEETS-SHEET 2- nndnu f mmvymvv J. E. SOONS AND Ht ROBINSON.

AUTOMATIC ARC REGULATOR.

APPLICATION FILED NOV. 15. 1919.

1,374,404. Patented Apr. 12,' 1921.

3 SHEETS-SHEET 3- 7 IN Vt? MTOR A TTO/M/EY.

, JAMES E. SOONS, OF

' and HARRY ROBINSON,

UNITED STATES PATENT oFncn,

NEW YORK, AND HARRY ROBINSON, OF'BROOKLYN, NEW YORK,

ASSIGNORS F ONE-HALF T0 EDWARD CATERSON, OF WOODLAWN, NEW "YORK, N. Y.

To all'whom it may concern:

Be it known that we, JAMES E. Soo1-rs respectively a subject of the King of the United Kingdom of Great Britain and Ireland arid a citizen of the United States, residing, respectively, at the borough of Bronx, city ofNew York, county of Bronx, and State of New York, and at the, borough of Brooklyn, city of New York, county of Kings, and State of New York, have invented certain new and usefullmprovements in Automatic Arc- Regulators, of which the following is a specification, referencebeing hadtherein to the accompanying drawings,which form a partthereof.

' Our invention relates to automatic arc regulators and more particularly to a mechanism which will maintain a substantially uniform length of the arc and constant intensity of the light. I y

-In arc lighting it has been the common practice to provide means actuated "as a result ofvariance in the potential of the circuit to the electrodes, 01' increased resistance feed one k it will automatically separate said carbons at the arc, which will automatically or both of the electrodes toward each other so as to intermittently restore the gap between the electrodes to that securing the-desired length of arc.-

This typeof regulating mechanism has .proven unsatisfactory in connection with highamperage arc lights used in cinematofgraphic projectors and similar mechanisms occasion any tensity of the light. The feed of the carbons ling ,the' arc, relied upon "wherein constant intensity of the light from the lamp is essential. Owing to this condltion it has 'been'a common practice toprovidemanually' operative means for controlthe skill of the operator being to maintain the desired length of are. H l

' In a regulator made in" accordance with our invention, the arrangement of parts and vthe electrical conditions are such that-the electrodes will be gradually advanced towardeach other with the burning of the carbons, the rate of advance being modified or controlled through the resistance at the aroma manner to prevent anyvsuch variation in the length of the arc gap as will noticeable change in the inlamp circuit at the arc.

. AUTOMATIC ABC-REGULATOR.

Specification of Letters Patent. Patented Apr. 12, 1921. Application filed November 15, 1919. serialno, aaaise. I

instead of being solely intermittent will be constant and proportioned more or less to an. automatic change inthe rate of feed as determined by a change of potential in the The feed will be accelerated or reduced as conditions demand, but the mechanism is so sensitivethat such changes will occur with so slight a variation in the resistance at th are, that there will be no sudden changes in the light effects.

In addition to the automatic regulation of the are gap, a regulator made in accordance with our invention may be set to form an arc of any desired length, it being pos-' sible to reset the mechanism to change the length of are while the lamp is burning, the carbons instantly coming to the position necessary for the desired length of arc, and beingmaintained in this relation.

When starting the lamp, our regulator will automatically bring the carbons into contact to establish the circuit therethrough,.

and immediately that the circuit is closed,

to strike the arc, and space the carbons to secure thedesired length of the arc.

f An essential characteristic of our invention is the employment of two electric motors coupled to a differential transmission mechanism adapted to actuate the electrodes, one of said motorsbeing set to runat conto variations of this potential due to variable,

of the resistance at the are as the result burning'of the carbon or other electrodes. The normal difference in the-speed of said motors, modified by the transmission mecha I nism, is such as to impart to the carbons a feeding movement approximating that required to maintain a constant length of the are, but mechanical difliculties, and irregularities in the consumption-of the carbons, make it impossible to exactly synchronize the regulator consumption,

10o mechanism with the carbon so that var1ances in the resistance at the arc is depended upon to cor'- rect an absence of such synchronism.

The invention consists primarily in an automatic arc regulator embodying therein means whereby relative movement may be imparted to the electrodes, a differential transmission mechanism, operative connections between said transmission mechanism and said means, a motor operative upon said transmission mechanism to impart thereto a. normal tendency to separate the electrodes, means whereby continuous constant power is developed in said motor, "and a motor having a different speed than first named motor operative upon said transmission mechanism to cause the electrodes to approach each other and connected in shunt with said electrodes, whereby the normal difference in speed of said motors will impart gradual feeding movement to said electrodes and the speed of said last named motor will vary with the resistance at the arc to compensate for irregularities in said feed, and in such other novel features of construction and combination of parts as are hereinafter set forth and described, and more particularly pointed out in the claims hereto appended.

Referring to the drawings Figure l is a side elevation of a regulator made in accordance with our invention, the lamp house being shown in section;

Fig. 2 is a diagram showing one system of wiring;

Fig. 3 is an end view of the transmission mechanism with the end plate removed;

Fig. 4 is a section on the line 44 of Fig. 3; and

Fig. 5 is a detail view of a conventional form'of the means by which relative movement may be imparted to the carbon carrier.

Like letters refer to like parts throughout the several views.

In the embodiment of our'invention shown in the drawings, we have illustrated it in connection with a constant potential lamp utilizing a volt D. C. current, this being the type of lamp ordinarily used for projectors. The electrodes ab are supported by suitable carriers (If-b slidable in the fitting 0 toward and from each other to permit the regulation of the arc. The carriers a'-?) each has a rack (1??) connected therewith, and mounted between and meshing with both said racks is a pinion c.

The fitting c is pivotally mounted at an adjusting screw 0 acting upon the arm 0 being provided, to permit the adjustment of the inclination of the electrodes. The above mechanisms are inclosed by the usual lamp house (I. I

The shaft 6 of the pinion 0 has a universal joint e in the length thereof to permit the angular adjustment of the electrodes, the end of this shaft being projected without the lamp housing (Z.

This construction is old and well known in this art, the racks a 7) and pinion. o and its appurtenances constituting the means for affecting relative movement of the electrodes, herein referred to.

Carried by that end of the shaft a without the housing (Z is a beveled gear by means of which said shaft may be rotated to regulate the arc.

Current for the lamp is drawn from the line f-g, the positive side of which has the usual rheostat f or other variable resistance for stepping down the voltage to that required at the arc. The line is controlled by an ordinary switch h.

In connection with the means for imparting relative movement to the carbons, we employ a differential transmission gearing operatively connected with the shaft 0 by a shaft i, one end of which carries a beveled gear 2" in mesh w'th the gear 0 and the other end of which is geared to' the said transmission mechanism. The shaft 71 is provided with suitable universal joints 'i i and one section thereof as 21 telescopes within another section as to facilitate the installation of the regulator in relation to a projector.

The shaft 6 is provided with a hand wheel 0 so connected therewith and with the gear 0 that the automatic regulator may be disconnected from the shaft 6 to permit the manual control of the electrode carriers to facilitate trimming of the lamp, oradjustment of the arc in the event of failure of the automatic control.

The differential transmission mechanism is actuated by two motors first of which is connected across the line fg to run at any predetermined constant speed, while the latter is connected in shunt with the arc, so as to 'htHGlVElllflblG- speed as determined by change of the potential of the arc circuit due to difference in potential of the circuit to, or variable resistance at, the arc.

The wiring system employed, Fig. 2, has been found satisfactory in use, but it is apparent that other systems may be employed to adapt our invention to different currents, or permit the use of different types of motors, without departing from the spirit and scope of the invention.

The motor A, as shown! in the drawings, is a shunt wount motor, the armature of which is connected across the line f-g' by the wires f g, and the shuntci'rcuit to the field j of which, has therein a rheostat or other variable resistance device by means of which the'speed of the motor may be changed.

The armature of the motor B is connected in shunt with the. arc circuit through the wires y -g and its field 0 is connected A and B, the,

across the line fg by means of the wires ing to the motor B. it acts as a shunt wound motor. but a drop of potential will not modify the field magnetism.

As will more fully appear hereinafter, the motor A acts upon the transmission so as to have a normal tendency to separate the electrodes (Z-Z), while the motor B acts in opposition thereto, or so as to have a normal tendency to cause the electrodes to approach.

To secure this condition we so design the motors A and B that with the highest voltage in the arc circuit, the speed of the motor B will be approximately that of the motor A with the full resistance f cut in the field shunt, and with the lowest voltage to be used at the arc, the speed of the motor B will be approximatel that of the motor A with all resistance cut out of the shunt circuit to the field j. In this manner, the speed of the motor A may be so changed as to not only insure the normal working speed of the motor B being higher than the constant speed of the motor A, but to also set the regulator for any desired length of arc.

lVhile it is not our intention to claim the specific transmission mechanism shown in the drawings in this application, such possesses certain characteristics essential to the regulator of our invention, and a more or less detailed description thereof will, therefore, be given.

This transmission comprises a casing on having mounted therein a shaft m. Keyed or otherwise secured to this shaft is a gear m meshing with a gear i carried by the shaft '2.

Idly mounted upon the shaft m are two the first of which carries a sun gear a and a worm gear 92 and the latter of which carries a sun gear 0' and a worm gear 0 The gear n is in mesh with a worm shaft 72. connected with the armature shaft of the motor A. while the gear 0 is in mesh with a worm shaft 0 connected with the armature shaft of the motor B, the arrangement being such that the hubs TIP-0 are driven in opposite directions, thus permitting actuation of the shaft 71 to either cause the electrodes to recede from, or approach, each other.

Carried by the shaft m is a fitting p havmg mounted at one side thereof two countershafts -r. The shaft I] carries two gears 7'-/ the former of which is in mesh with the gear a, while the. shaft 1' carries two gears r'r the former of which is in mesh with the gear 0, and the latter of which is in mesh with the gear Q2. The intermediate gears (f -r permit the planet gears q-r to be rotated with their respective sun gears 17-0. The counterweight 8 carried by the fitting 79 substantially diametrically opposite the shafts r is provided to insure easy and uniform running of the planet gear system.

- proximately 55 volts to the By transmitting power to the transmission mechanism by means of worm shafts driven by the motors AB, not only is a desired reduction of speed secured, but the conversion of the two connected motors into a motor generator set as the result of one motor driving the armature of the other, is prevented. While this condition would not generate sufficient current to choke-the line, it would prevent the driving of the shaft m as a result of the differential speed of the two sun gears, which would destroy the effectiveness of the regulator.

In describing the operation of the herein described regulator, reference will be had to the specific mechanical and electrical conditions presented in the drawings, the line current being 110 volts D. C. and the resistance 7" being so set as to deliver apelectrodes at an 60, it being unan arbitrary amperage of approximately derstood that this is merely selection of conditions.

In starting the device, the resistance 9'' will be out in to deliver any desired voltage, less than 110 volts, to the field of the motor A. say 55 volts.

hen the switch it is closed in starting, the gap between the electrodes arb will prevent the flow of any current through the arc circuit, the entire strength of, the current flowing through the shunt circuit F-g to the armature of the motor B, which current will be in excess of that for which the arc circuit is set. At the same time the field 717 will be energized by a current at the full voltage of the line. The closing of the line circuit will also place the armature of the motor A in circuit, with the full voltage of the line, and the field y of said motor in cir- 1'05 cuit with the line, with the resistance out in, 1 as heretofore stated.

\Vith these conditions established, both motors A and B will start. the motor A immediately picking up until it reaches that speed for which the rheostat g is set, while the motor B by reason of the increased current to its armature will develop a speed in excess of that which will be developed by the voltage for which the arc is set.

Thereafter, while the regulator is in operation, the motor A will continue to run at a constant speed subject, however, toslight fluctuations due to conditions on the "line, while the speed of the motor B will vary in a manner which will be more particularly described hereinafter.

The rotation of the shaft 72 by the motor A will drive the sun gear a at a constant speed, while the rotation of the gear 0 will 1 drive the sun gear 0 at a speed proportionate with that of the motor B, both gears, however, being driven at a much reduced speed by reason of the transmission mechanism. Since the highest possible speed of the motor B when the arc is set for the highest voltage desired to be used, is approximately the speed of the motor A with the separating the electrodes and striking entire resistance cut into ,the field shunt, it is apparent that with no current passing through the electrodes, the speed attained by the ,motor B will be in excess of that which it will attain after the arc has been struck, so that there will be a considerable difference of speed at this period between the'gears o and a, thus causing the fitting p to rotate about the axes of said sun gears, thus rotating the shaft 'm and through it the, shaft 2', and through the gears i and 6 the shaft 6. This causes the electrode carriers af-b' to approach each other until the electrodes are in physical contact. 7

The instant the electrodes touch, the arc circuit will be short circuited through the. electrodes, practically cutting out the shunt.

circuit f g to the armature of the motor B. During all this time the motor A and the sun gear 11 willbe rotating at constant.

speed so that with the stoppage of the motor B, the conditions will be reversed, the speed of the gear at exceeding that of the gearo",

which is practically at rest, thus quickly the arc and continuing to separate them until the resistance at the arc reaches that determined bythe rheostatf' and the rheostat '9; With the striking of the arc, current will flow to the armature of the motor B, which will begin to turn, gradually gathering speed as the resistance at the arc increases, until it attains its maximum speed with a given length of arc. This speed is always slightly in excess of the constant speed of the motor A so that while the arc is .burnmg, the fitting p will be always turning,

'but very slowly, under the. control of the gear 0', thus imparting a constant minute eeding movement to both carbons, which movement. is'substantially coincident with the rate of consumption of the carbons.

If, forany'reasomsuch as imperfections in the carbons, or lack of accuracy in the different mechanisms, the rate of consumption of the carbons be less than the rate of their approach under the control of themotor B, the resistance at the arc will be reduced and the speed of the motor B will; be correspondingly reduced, so that the motor A, which has a normal tendency to 1 separate the electrodes, will become oper ative to retard the feed until the normal gap is restored. If, on the other hand, the rate of consumption of the carbon is greater than therate of feed, the resistance at the arc will be increased and there will be a corresponding increase in the'speed of the motor B, thus accelerating the feed until the normal arc is reached. These fluctuations,

however, are very small, the operation of f'the motor A with relation to that o the motor B. This, when striking the are, prolongs the interval before the motor B attains its maximum speed with the new are resistance, although thereafter the feeding conditions will be'substantially as heretofore referred to. l

Likewise if it is desired to shorten the gap, resistance will be cut out of the shunt field, thus reducing the speed of the motor A so that the motor B will attain its maximum speed with the new arc length ;in a shorter interval. Thereafter the motors A and B run at substantially the same relative speeds as with the longer arcs, feed always being uniform and proportionate to the carbon consumption.

In actual practice, we have found that the fluctuation in the. resistance at the .arc,

I seldom exceeds one-tenth of a volt and that these fluctuations occur at different intervals, and that 'whenthere is a variance in such resistance the speed of the motor B will instantly respond to correct this condition, and that response is the same whether the resistance increases or decreases. The result is a substantially. uniform len th of arc and constant light ntensity, whic particularly' adapts the regulator v for use in,

cinematographic projectors, and similar devices requiring this condition.

.While in actual'practice we have found the particular transmission" mechanism and -wiring arrangement shown in the drawings,

to give highlysatisfactory.results, it is apmaterial, since such" are susceptible of wide parent that the specific detailsof'said mech-; 'anism' and said electrical conditions; are imvariation,-'.while 1 preserving the essential --characteristics of the regulator. If desired the motorconstruction may be modifiedto adapt the invention to --anA.iC. line For to different voltages upon alIljC. or an A. C. line. ,The speeds ofthe :motors A and B' may be governed by changes in the potential of'the armature circuits instead of the field,

and vice versa. In fact the electrical. conditions are subject to that wide range of variations within vthe'skill of the ordinary electrician, while still preserv'ing'the essential characteristics of the invention.

The motor A instead of being driven from the same mains as those supplying power to the arc, may be driven from entirely different mains, it being essential, however, that the arc motor,or motor B, be connected in ins shunt with the electrodes. For convenience of expression in the claims, the motor A will be referred to as the line motor and the motor B as the arc motor. said terms being considered with due regard to the possible wide range of electrical conditions above referred to.

hile, in actual practice, it is preferable to use an electric motor having constant speed. it is apparent that since the invention merely requires that one element of the differential be rotated at substantially constant speed, the source of power for actuating this element, considering the invention broadly, is immaterial.

Having described the invention, what we claim as new and desire to have protected by Letters Patent is 1. An automatic are regulator embodying therein means whereby relative movement may be imparted to the electrodes, a differential transmission mechanism, operative connections between said transmission mechanism and said means, a motor operative upon said transmission mechanism to impart thereto a normal tendency to separate the electrodes, means whereby continuous constant power is developed in said motor, and a motor having a different speed. than said first named motor operative upon said transmission mechanism to impart thereto a normal tendency of the electrodes to approach each other and connected in shunt with said electrodes, whereby the normal difference in speed of said motors will impart gradual feeding movement to said electrodes and the speed of said last named motor will vary with the resistance at the arc to compensate for irregularities in said feed.

2. An automatic arc regulator embodying therein means whereby relative movement may be imparted to the electrodes, actuating means therefor comprising two motors, a differential transmission mechanism actuated thereby, means whereby continuous constant power is developed in one of said motors while the arc is burning, to impart to said mechanism a normal tendency to separate the electrodes, and means whereby the other motor will be rotated at variable speed in accordance with change of poten tial due to variable resistance at the are, whereby said motors are operative through said transmission mechanism to cause the electrodes to approach each other at a speed governed by the differencein speed of said motors.

3. An automatic are regulator embodying therein means whereby relative movement may be imparted to the electrodes, actuating means therefor comprising a differential speed transmission mechanism operatively connected with said means, means whereby continuous constant power will be applied to said transmission mechanism to impart thereto a normal tendency to separate said electrodes, and independently operative means having variable speed determined by change of potential due to variable resistance at the arc while the lamp is burning, said last named means having a normal tendency to cause said electrodes to approach each other, and having a normal relatively higher speed than said first named means, whereby when the are is burning, there will be a gradual uniform feed ofthe electrodes with relation to each other at substantially the same rate as the consumption of the carbons.

4. An automatic arc regulator embodying therein means whereby relative movement may be imparted to the electrodes, a line motor continuously rotated at constant speed having a normal tendency to separate said electrodes, an arc motor connected in shunt with the electrodes, whereby it will rotate at variable speeddetermined. by change of potential due to variable resistance at the are, and a differential transmission mechanism acted upon by said motors respectively and operatively connected with said first named means.

5. An automatic arc regulator embodying therein means whereby relative movement may be imparted to the electrodes, a differential transmission mechanism, operative connections between said transmission mechanlsm and said means, a motor operative upon said transmission mechanism, to impart thereto a normal tendency to separate the electrodes, means whereby continuous con-' stant power is developed in said motor, a motor having a different speed than said first named motor operative upon said transmis sion mechanism to cause the electrodes to approach each other and connected in shunt with said electrodes, whereby the normal difference in speed of saidmotors will impart gradual feeding movement to said electrodes and the speed of said last named motor will vary with the resistance at the arc to compensate for irregularities in said feed, and a speed changing device operatively connected with said first named motor, whereby the length of the are gap may be varied through a change of speed in said motor.

6. An automatic arc regulator embodying therein means whereby relative movement may be imparted to the electrodes, a line motor continuously rotated at constant speed having a normal tendency to separate said electrodes, an arc motor connected in shunt with the electrodes, whereby it will rotate at I varied through a change of speed in said motor, and a differential transmission mechanism acted" upon by said motors respectively and operatively connected with said first named means.

7. An automatic arc regulator embodying therein means whereby relative movement may be imparted to the electrodes, a differential transmission mechanism, operative connections between said transmission mechanism and said means, a motor operative upon said transmission mechanism, to impart thereto a normal tendency to separate the electrodes, means whereby continuous constant power is developed in said motor, a motor having a different speed than said first named motor operative upon said transmission mechanism to'cause the electrodes to approach each other and connected in shunt with said electrodes, whereby the normal difference in speed of said motors will impart gradual feeding movement to said electrodes and the speed of said last named motor will vary with the resistance at the arc to compensate for irregularities in said feed, and a variable resistance member included in the circuit to one of the elements of said constant speed motor, whereby the length of the arc gap may be varied through a change of speed in said motor;

8. An automatic arc regulator embodying therein means whereby relative movement vmay be imparted to the electrodes, a line motor continuously rotated at constant speed having a normal tendency to separate said electrodes, an arc motor connected in shunt with the electrodes, whereby it will rotate at variable speed determined by change of potential due to variable resistance at the arc, a variable resistance member included in the circuit to one of the elements of said constant speed motor, whereby the length of the arc gap may be varied through a change of speed in said motor, and a differential transmission mechanism acted upon by said motors respectively and operatively connect ed with said first namedi means.

9. An automatic arc regulator embodying therein means whereby relative movement 7 may be imparted to the electrodes, a differential transmission mechanism, operative connections between said transmission mechanism and said means, a constant speed motor operative upon said transmission mechanism, and a motor having a different speed than said first named motor also operative upon said transmission mechanism and connected in shunt with said electrodes, whereby the normal difference in speed of said motors will impart gradual .feeding' movement to said electrodes and the speed of said last named motor will vary with the resistance at the arc to compensate for irregularities in said feed, said transmission motors to the other is prevented.

10. An automatic arc regulator embody ing therein means whereby relative move ment may beimparted to the electrodes, differential transmission mechanism, opera tive connections between said transmissioi mechanism and said means, a constant speeC motor operative -upon said transmissior mechanism, a motor having a different speet than said first named motor also operativ upon said transmission mechanism and connected in shunt with said electrodes, whereby the normal difference in speed of said motors will impart gradual feeding movement to said electrodes and the speed of said lastnamed motor will vary with the resistance at the arc to compensate for irregularities in said feed, and a speed changing device operatively connected with said first named motor, whereb the length of the arc gap may be varied through a change of speed in said motor, said transmission mechanism embodying therein means whereby transmission of power from one of said motors to the other is prevented.

11. An automatic are regulator embodying therein means whereby relative movement may be imparted to theelectrodes, a line motor continuously rotated atl constant speed having a normal tendency to separate said electro s, anarc motor connected in shunt with the electrodes, whereby it will rotate at variable speed determined by change of potential due-to variable resistance at the arc, a speed changing device operatively connected with said first named motor, whereby the length of the arc ap may be varied through a change of spee in said motor, and a differential transmission mechanism acted upon by said motors respectively and operatively connected with said first named means, said transmission mechanism embodying therein means whereby transmission of power from one of said motors to the other is prevented.

12. An automatic arc ing therein means whereby relative movement may be imparted to the electrodes, a shunt wound line motor connected across the line, a variable the field of saidmotor, an arc motor, the

armature of which is connected in shunt with the electrodes, and the field of which I is connected" across the line, whereby said line motor will run at constant speed as resistance, and

regulator embody- I resistance in circuit with variable speed acted upon by said separate the electrodes, 1

and said are motor heing operative through said transmission mechanlsm to .cause the electrodes to approach each other ata speed go erned by the difference in speed of said motors, and operative connections-between said transmission mechanism and said first named means. r a a In witness whereof we have hereunto affixed my signatures, in the presence of two subscribing witnesses, this 3rd day of No- 10 vember, 19l9.

JAMESE. SOONS. HARRY ROBINSON. Witnesses:

FRIEDA KOEHLER, -HARRIET Ln BERTHON. v 

